Method of forming slotted panels



C. L. IRVIN METHOD OF FORMING SLOTTED PANELS Sept. 27, 1966 5 Sheets-Sheet 1 Filed Jan. 16, 1963 Y &m m m wmflw L. F- L R A H C m Sept. 27, 1966 c. L. IRVIN 3,275,727

METHOD OF FORMING SLOTTED PANELS Filed Jan. 16, 1963 5 Sheets-Sheet 1N ENTOR. CHARLES L. RVIN ATTORNEY C. L. IRVIN METHOD OF FORMING SLOTTED PANELS IN\/ ENTOR. HARLES L.IRvm

Sept. 27, 1966 Filed Jan. 16, 1963 United States Patent 3,275,727 METHGD (31F FORMING SLQTTED PANELS Charles L. Irvin, Neshanic, NJL, assignor to Johns-Manville Corporation, New York, N.Y., a corporation of Delaware Filed Jan. 16, 1963, Ser. No. 251,888 18 Claims. (Cl. Zed-M6) This invention relates to a method for forming slotted panels; more particularly, it relates to a novel method for forming a slot in an edge of a composition board without requiring a sawing operation.

Although wood has been and continues to be utilized as an exterior siding material, various wood substitutes have been introduced over the years in efforts to reduce costs and to minimize the effects of weathering. In most cases, exterior siding panels formed of materials other than wood have been made relatively thin for purposes of economy and/or weight reduction. In order to create the impression of the thick butt portion of wooded clapboards, special fastening devices have been required to attach the relatively thin panels to a building structure in such a manner as to space the lower edges of the panels from the structure.

One such fastening device, which not only creates the impression of panel depth but also permits fastening nails to be hidden from view, is a sheet metal fastener strip having an upstanding flange portion adapted to be received in a slot in the butt edge of a siding panel, thereby spacing the panel from the building structure. This method of attaching exterior siding panels to a building structure heretofore has been limited to panels having edges of a thickness permitting them to be sawed to form a slot for receiving the flange of the fastener strip. For this reason, it has not been practicable to manufacture fibrous-cement siding panels with a slotted edge because the thickness required to permit an edge sawing operation would cause the panel to be too heavy and costly.

An object of the present invention is to provide a method of forming a relatively thin composition panel with a slotted edge.

Another object of the invention is to provide an economical method of slotting the edge of a fibrous-cement panel without requiring a sawing operation.

A further object is to provide a relatively thin fibrouscement panel with a slotted edge.

Briefly, the method of slotting the edge of a fibrouscement panel according to the present invention involves the steps of applying a stripe of parting agent to a partially built-up composition sheet, completing the formation of the sheet, cutting the sheet into panel widths along the parting stripe so that each. resulting panel is provided with a parting line intermediate the panel faces adjacent an edge, spreading the panel faces adjacent the parting line to form a slot, and lodging material in the slot to hold the faces separated. Instead of applying the stripe along a line intermediate the sheet edges, it may be applied along an edge if it is desired to form a large panel with a slotted edge. By this novel method, a slot of suilicient Width to receive the upstanding flange of a panel fastener strip may be formed in a relatively thin (about A; inch) fibrous-ccment panel, such as one formed of asbestos-cement, without removing any of the panel material.

The nature of the invention will be more fully understood and other objects may become apparent, when the following detailed description is considered in connection with the accompanying drawing, wherein:

FIG. 1 is a partial pictorial representation of a slotted exterior siding panel attached to a building structure;

FIG. 2 is a diagrammatic side elevational view of a portion of a Hatschek machine;

3,275,727 Patented Sept. 27, 1956 FIG. 3 is a plan View of the structure shown in FIG. 2;

FIG. 4 is an enlarged sectional view taken on lines 4-4 of FIG. 3, and showing the parting agent applicator in operative position;

FIG. 5 is a sectional view similar to FIG. 4, but showing the parting agent applicator in inoperative position;

FIG. 6 is a plan view of a composition sheet as it enters the trimming station;

FIG. 7 is a side elevational view of a panel at the slot separating station;

FIG. 8 is an enlarged sectional view taken on lines 38 of FIG. 7.

FIG. 9 is an enlarged sectional view taken on lines 9-9 of FIG. 7;

FIG. 10 is a plan view of a composition panel at a modified slot separating station; and

FIG. 1'1 is an enlarged sectional view taken on lines 11-411 of FIG. 10.

Referring to the drawing, a typical installation of slotted exterior siding panels is illustrated in FIG. 1, wherein siding panels 20 are secured to a building structure 22 by nails 24 driven through the upper portions of the panels. Engaging the upper portions of the panels 20 and also secured to the building structure 22 by the nails 24 are fastener strips 26 having upwardly extending flanges 28 spaced from and connected to the main body of the fastener strip by an outwardly extending portion 30. The flanges 28 are received in slots: 32 formed in the lowermost edges of the panels 20, thereby supporting the panels 20 and spacing the butt edges thereof from the building structure 22 to create the appearance of a thick butt portion. Heretofore, this general arrangement has been utilized only with exterior siding panels of suflicient thickness to have a slot sawed in the butt edge thereof, and has been limited to panels made of relatively lightweight materials, such as fiberboard. Accordingly to the present invention, relatively thin siding panels of about 4; inch thickness may be formed from relatively dense materials, such as fibrous-cement, and while the following discussion specifically refers to fibrous-cement sheets, it should he understood that the invention also applies to built-up composition sheets of other substances.

Fibrous-cement boards commonly are formed on a Hatschek machine, which comprises a continuous belt or felt held in engagement with a portion of the circumference of a relatively large accumulator roll by a relatively small opposition roll. A screen covered cylinder rotates in a slurry of fibrous-cement mixture, picking up fibrous-cement solids and transferring them to the felt, which in turn transfers them to the rotating accumulator roll. A layer of solids, often referred to in the art as a wrap, is picked up by the accumulator roll during each rotation thereof, and a mat of predetermined thickness is formed by rotating the accumulator roll a predetermined number of turns, thus building up a laminate of solids. By stripping the mat from the accumulator roll, an uncured fibrous-cement sheet is obtained, which sheet is then cured and may be subjected to other operations, such as trimming and coating.

Referring to FIG. 2, which illustrates a portion of a Hatschek machine, an accumulator roll is indicated at 34, the opposition roll at 36, and the continuous felt, which conveys the fibrous-cement composition to the accumulator roll, at 38. A conveyor 40, trained about drum 42, is positioned to transport a sheet which has been stripped from the accumulator roll toward further handling stations.

According to the present invention, a number of layers or wraps of material corresponding to a portion of the desired sheet thickness are built up on the accumulator roll, and one or more stripes of a parting agent are then applied to the partially built-up mat. The parting agent may be any suitable substance which does not adhere to a subsequent layer of material picked up by the accumulator roll. Oil mixtures have been found to work well as parting agents, one such mixture, by volume, being 90% kerosins and 10% industrial oil. The number of parting stripes applied to the partially built-up mat depend upon the desired width of the sheets to be produced. For purposes of illustration, in FIGS. 2 and 3 two applicators 44 are provided adjacent the accumulator roll at points spaced from the side of the roll about onehalf of the distance between the applicators. This arrangement permits four slotted panels to be formed from each sheet stripped from the accumulator roll.

The parting agent applicator may be of any suitable design, the structure illustrated in FIGS. 4 and 5 comprising a felt covered roll 45 rotatably mounted on support arms 46 connected to a shaft 48. The oil supply means and the means for moving the applicators 44 about the shaft 48 have been omitted for purposes of clarity since these features are well known in the art. As illustrated in FIG. 4, after several layers or wraps of material have been built up on the accumulator roll 34, the applicators 44 are lowered into engagement therewith to apply stripes of parting agent 52 over the surface of the laminations 50. As shown in FIG. 5, after the parting agent stripes have been applied to the laminations 50, the applicators 44 are withdrawn to inoperative position, after which additional wraps 54 are built up until the desired thickness is attained.

After the material has been built up to the desired thickness, it is stripped off the accumulator roll 34 as a sheet 56, to be trimmed along the stripes of parting agent 52 to provide a number of smaller units, each having a parting line intermediate the panel faces along an edge thereof. As illustrated in FIG. 6, the trimming operation may be accomplished by moving the sheet 56 through a slitting station where a shaft 60 has a number of rotary cutting discs 58 mounted thereon. The number of cutting discs provided depends upon the number of parting agent stripes which have been applied to the sheet 56 and also upon the desired width of the smaller panel units. In the arrangement illustrated in FIG. 6, two stripes of parting agent have been applied to the sheet 56 along lines spaced from the side edges of the sheet a distance equal to about one-quarter of the width of the sheet. By slitting the sheet 56 centrally thereof and also along each of the parting stripes 52, four smaller panel units are provided, each having an edge with a parting line extending along the length thereof. If desired, the edges of the sheet 56 may also be trimmed. It should be understood that the cutting or trimming operation may take place either after the sheets have been fully cured or before curing; a wet slitting operation preferably is employed if the sheets are trimmed while uncured.

Referring now to FIG. 7, after the sheet 56 has been trimmed or cut into smaller panel units 62, the trimmed sheets or units are fed through an edge separating station. For purposes of illustration, the panel unit 62 is shown being transported by feeding rollers 64, only one of which is illustrated, past a spreader blade 66, the major faces of the panel unit being in an upright position. The spreader blade 66 may be of any suitable design but is illustrated as a rotary disc 69 mounted on a shaft 70 to engage an edge of the panel unit 62 along the parting line formed by the stripe of parting agent. This operation separates the sides or major faces of the panel adjacent the parting line, thereby forming a slot 72. Completely uncured sheets or panels should not be exposed to the spreading operation since they do not possess sufii cient strength to withstand the stresses of the operation; instead, the sheets should be at least partially cured to a degree whereby they are able to withstand the stresses. Immediately after the panel faces have been spread apart, and while the faces are still separated, particulate material 74, such as sand, for example, is dropped into the open slot 72 from a suitable dispenser 68. The sand lodges at the bottom of the slot, acting as a wedge to maintain the panel edges separated. If desired, an air jet, not shown, may be provided at an appropriate location to blow excess sand from the slot. After the slot forming operation, the panel 62 is completely cured, if it had been only partially cured at the time of the spreading operation, after which it may be subjected to other finishing operations, if desired.

Instead of providing panel lengths having only one slotted edge, both elongated edges may be provided with slots. This is accomplished by slitting the sheet 56 only along the stripes of parting agent which have been applied thereto and not along a line medially of the stripes as described above. This would require the application of stripes of parting agent to the edges of the sheet 56 at an intermediate stage in its formation on the accumulator roll. It would not be necessary to make the edge stripes as wide as the intermediate stripes since the edge stripes provide a parting line for only one edge and not for two, as the other stripes .do. Referring to FIGURE 10, a panel 62, which has had a parting stripe applied at both edges, is fed by feed rolls 76 through a spreader station, the major faces of the panel being horizontally disposed. Horizontally disposed spreader blades 78 separate the major faces of the sheet 62 adjacent both edges thereof in the same manner as the spreader blades 66, described above in connection with the arrangement shown in FIG- URES 7-9. Since the formed slots 72 are horizontally disposed, it is necessary to provide a modified sand injector or dispenser. As shown in FIGURE 11, each sand dispenser 80 is similar to the dispenser 68 illustrated in FIGURE 7 and 9, with the exception of a curved chute 82 extending from the mouth of the dispenser 30 into the slot 72. This construction enables the sand or other particulate matter dropping from the dispenser St) to be guided by the chute 82 into the slot '72. A panel with two slotted edges saves time in the erection of a building structure, since workmen need not spend time looking for the slotted edge of the panel, but may use either edge.

In summary, a fibrous-cement sheet is formed to partial thickness on an accumulator roll of a Hatschek machine, after which one or more stripes of a parting agent are applied to the surface of the partially built-up sheet. The sheet is then built up to final thickness, after which it is stripped from the accumulator roll and trimmed along the parting agent stripes either before or after curing. After at least partially curing the sheets to a point where they possess sutficient strength to withstand the stresses of the separating or spreading operation, the parting lines are separated, and sand or other particulate material is deposited between the separated edges to hold them apart. Although excellent results have been obtained using sand or other particulate material, any other substance adapted to provide the same function could be utilized.

In practice, asbestos-cement panels of only /a inch thickness have been formed with slotted edges, the parting agent having been applied after half of the layers or wraps of material have been built up on the accumulator roll. Asbestos-cement composition on either side of the parting agent stripe has displayed to tendency to adhere even when subjected to a repressing operation.

It should be understood that while the present invention has been described particularly with respect to fibrous-cement sheets, it is not limited thereto but also may apply to other composition sheets which are formed on equipment permitting the application of a parting agent to a partially builtup sheet. It also should be understood that the invention is not limited only to sheets adapted for use with fastener strips for application to a building structure, but it is also applicable to sheets formed with edge slots for other purposes. It is not necessary in practicing the invention to cut the sheets into smaller uni-ts, since a parting agent may be applied to an edge of the original relatively large sheet for the purpose of producing a large panel with a slotted edge.

It is to be understood that other variations and modifications of the present invention may be made without departing from the spirit of the invention. It also is to be understood that the scope of the invention is not to be interpreted as limited to the specific embodiments disclosed herein but only in accordance with the appended claims, when read in the light of the foregoing disclosure.

What I claim is:

1. A method of forming slotted composition panels, comprising the steps of:

(a) forming a composition sheet to partial thickness,

(b) applying at least one stripe of parting agent to the partially built-up composition sheet,

(c) completing the fonmation of said sheet to final thickness,

(d) severing the sheet along the stripe to form panel units, each with a panting line along one edge thereof,

(e) separating the faces of the panel units along the parting lines thereof to form slots, and

( f) depositing material into the slots to maintain the faces separated.

2. A method of forming slot-ted composition panels as recited in claim 1, wherein the material deposited into the slots in particulate.

3. A method of forming slotted composition panels as recited in claim 1, wherein the sheet is comprised of a fibrous-cement composition.

4. A method of forming slotted composition panels as recited in claim 3, wherein the fibrous-cement composition comprises asbestos-cement.

5. A method of forming slotted composition panels as recited in claim 1, wherein the parting agent is oil.

6. A method of forming slotted panels from a built-up composition sheet having at least one stripe of parting agent extending between successive layers of the built-up composition, comprising the steps of (a) severing the sheet along the stripe to form panel units, each with a parting line along one edge thereof,

(b) separating the faces of the panel units along the parting lines thereof to form slots, and

(c) depositing particulate material into the slots to maintain the faces separated.

7. A method of forming slotted composition panels as recited in claim 6, wherein the sheet is comprised of a fibrous-cement composition.

8. A method of fonming a slotted composition sheet comprising the steps of (a) forming a composition sheet to partial thickness,

(b) applying a parting agent to the partially built-up composition sheet adjacent an edge thereof,

(c) completing the formation of said sheet to final thickness,

(d) separating the faces of the sheet along the parting line to form a slot in said edge, and

(e) depositing material into the slots to maintain the faces separated.

9. A method of forming slotted composition panels as recited in claim 8, wherein the material deposited into the slots is particulate.

10. A method of forming slotted composition panels as recited in claim 8, wherein the sheet is comprised of a fibrous-cement composition.

11. A method of forming slotted composition panels as recited in claim 10, wherein the fibrous-cement composition comprises asbestos-cement.

12. A method of forming slotted composition panels as recited in claim 8, wherein the parting agent is oil.

13. A method of forming a slotted sheet from a builtup composition sheet having a parting agent between successive layers of the built-up composition adjacent an edge thereof, comprising the steps of:

(a) separating the faces of the sheet along the parting line to form a slot in said edge, and

(b) depositing particulate material into the slots to maintain the faces separated.

14. A method of forming slotted composition panels as recited in claim 13, wherein the sheet is comprised of a fibrous-cement composition.

.15. A method of forming slotted fibrous-cement panels, comprising the steps of:

(a) forming a brous-cement sheet to partial thickness,

(b)applying at least one stripe of parting agent to the partially built-up fibrousoernent sheet,

(c) completing the fonmation of the sheet to final thickness,

(d) at least pantially curing the sheet,

(e) severing the sheet along the stripe to form panel units, each with a parting line along one edge thereof,

(f) separating the faces of the panel units along the parting lines thereof to form slots, and

(g) depositing material into the slots to maintain the faces separated.

16. A method of forming fibrous-cement panels as recited in claim 15, wherein the material deposited into the slots is particulate.

17. A method of forming fibrous-cement panels as recited in claim 15, wherein the parting agent is oil, and the fibrous material is asbestos.

18. A method of forming fibrous-cement panels as recited in claim 15, wherein the sheet is substantially completely cured prior to being severed.

References Cited by the Examiner UNITED STATES PATENTS 652,150 6/1900 Terpening 52539 1,567,946 12/1925 Helflinger 50246 1,818,009 8/1931 Robinson 264146 1,819,199 8/1931 Robinson 264146 2,324,218 7/1943 Kraus 52-639 2,421,407 6/ 1947 Bowman 50246 2,452,640 11/ 1948 Elmendorf 52--471 2,526,634 10/1950 Chavannes 264264 2,587,171 2/1952 Knewstubb et a1. 156254 XR 2,748,048 5/1956 Russell 156- 289 XR 2,990,309 6/1961 Wahl et a1 156-289 XR 3,207,826 9/1965- Yost 264158 ROBERT F. WHITE, Primary Examiner.

EARL I. WITMER, Examiner.

M. R. DOWLING, Assistant Examiner. 

1. A METHOD OF FORMING SLOTTED COMPOSITION PANELS, COMPRISING THE STEP OF: (A) FORMING A COMPOSITION SHEET TO PARTIAL THICKNESS, (B) SO AS TO TEAR THE PORTION EXTRUDED PRIOR TO SAID PARTIALLY BUILT-UP COMPOSITION SHEET, (C) COMPLETING THE FORMATION OF SAID SHEET TO FINAL THICKNESS, (D) SEVERING THE SHEET ALONG THE STRIPE TO FORM PANEL UNITS, EACH WITH A PARTING LINE ALONG ONE EDGE THEREOF, (E) SEPARATING THE FACES OF THE PANEL UNITS ALONG THE PARTING LINES THEREOF TO FORM SLOTS, AND 